With the progress of optoelectronic and semiconductor technology, there has also been great development on flat panel display devices. Among various flat displays, due to various superior properties including high space utility, low power consumption, no radiation, and low electromagnetic interference, liquid crystal display (LCD) has become the mainstream of the market.
Generally, a liquid crystal display device includes a liquid crystal panel and a backlight module (BL). Since the liquid crystal panel itself does not emit light, the backlight module must be placed under the liquid crystal display panel to provide surface light source necessary for the liquid crystal display panel. Thus, the liquid crystal display panel can display image with the surface light source provided by the backlight module.
In recent years, curved liquid crystal display devices have been continuously produced by many companies. Generally, curved LCD devices provide superior viewing effect from an edge to another edge. However, typical flat LCD devices have inferior displaying effect at the screen edge. Entire screen of the curved LCDs has curve shape enclosing towards observers, which in turn provides wide full image effect. No matter on the screen center or at the edges, curved LCDs can bring the same visual enjoyment. When users observe from near distance, off-axis viewing distortion can be decreased. In addition, curved LCDs can lengthen the viewing distance for observers, achieving better viewing experience. For most of current curved LCD devices, edge-type curved backlight modules are used for provide light source to the curved LCD panels.
FIG. 1 is a diagram showing a conventional curved liquid crystal display device. As shown in FIG. 1, the curved liquid crystal display device includes a backlight module 1, a sealant 2 disposed on the backlight module 1, a liquid crystal display panel 3 disposed on the sealant 2, and a front frame 4 disposed on the liquid crystal display panel 3. The backlight module 1 includes a back board 11, a curved light guide plate 12 disposed in the back board 11, a backlight source 13 disposed in the back board 11, and a heat dissipation plate 14 used for installing the backlight source 13. A reflection plate 15 is further disposed between the back board 11 and the curved light guide plate 12. An optical film set 16 is further disposed on the curved light guide plate 12. Moreover, the reflection plate 15 and the optical film set 16 have the same curve shape as the curved light guide plate 12 has.
The front frame 4 includes a front board 41 and the side board 42 connected to the front board 41. The front board 41 is in curve shape, and the side board 42 is in vertical shape. The front board 41 and the side board 42 are connected with an acute angle. Generally, the front frame 4 is obtained by punching a metal material. FIG. 2 is a diagram showing punching for the conventional front frame. The mold for shaping mainly includes an upper mold plate 43 having an upper coping surface 43a, a lower mold plate 44 having a lower coping surface 44a, and a bending slide 45. During punching, front board 41 with curve shape is placed between the upper coping surface 43a and the lower coping surface 44a and shaped. Since the front board 41 and the sideboard 42 are closely connected, the sideboard 42 is directly bended along Y direction by means of the bending slide 45. Since the transition region 4a between the front board 41 and the side board 42 is exactly at the bending location, and the front board 41 and the side board 42 is connected in a non-right angle, it is difficult to control the bending accuracy and to limit the rebounding amount of the sheet metal during bending. Thus, the curve shape of the front board 41 of the front frame is not easy to control. The shape dimension of the front board 41 is not stable, affecting the quality of the display module.